Insects and related pests are commonly known to damage agricultural crops. The damage to the crops adversely affects the yield of such crops. One such pest known to damage crops is the nematode. There are many types of nematode pests, one such nematode is the soybean cyst nematode (SCN), Heterodera glycines Ichinohe. SCN causes substantial losses in soybean production. Yield suppression attributed to H. glycines resulted in an estimated $750 million in losses to U.S. soybean producers annually from 2003 to 2005 (Wrather, J. A., and Koenning, S. R. 2006. Estimates of disease effects on soybean yields in the United States 2003 to 2005. J. Nematol. 38:173-180).
Generally, seed treatments can protect the developing seedling from seed and soil borne pathogens and insect pests, as well as early foliar diseases and insects. Seed treatments can control pathogens and insects with very much reduced rates of active ingredient (a.i.) compared with soil or foliar applications. As the a.i. is restricted to the region around the seed and to those pathogens and insects attacking the developing seedling, seed treatments give biological, environmental and economical benefits.
Some varieties of soybean have been bred to express a characteristic in the plant which reduces damage due to the SCN. Soybean genetic resistance to SCN have been found in various resistant sources, for example, Plant Introduction (PI) lines PI88788, PI548402 and PI437654 are resistant cultivars available to soybean producers for use in breeding programs against SCN. PI88788, for example, is the source of resistance for a large percentage of soybeans grown in the soybean market. PI8878 is popular with growers because of its ability to deliver resistance in combination with high yield, among other reasons.
However, in light of the methods currently used to control nematode pests, applicants believe there remains a further need for increased control of nematode pests. Certain pest control methods are proposed in the literature. However, these methods are not fully satisfactory in the field of pest control, which is why there is a demand for providing further methods for controlling and combating pests and for protecting plants, especially crop plants. This object is achieved according to the present technology. There is also a need to reduce the rate at which pests acquire an increasing tolerance to both pest resistant crop plants and pesticides. For example, applicants desire to reduce the rate at which pests acquire resistance to lines having, inter alia, high yield, such as PI88788 for example. Applicants also desire to extend the useful life of both pest resistant crop plants and pesticides.